I have to go back to the store soon to get more food. Last time I grabbed a small bag of chick food that was medicated. I have 4 chicks that are a little over a week old and 3 chicks that are four days old. Should I get the same feed that I did before in a larger quantity (if they sell it)? Or can I switch feeds to another chick starter that isn't medicated? Will it be rough on them to switch?